Railway unit cushioning apparatus

ABSTRACT

A cushioning apparatus operable to be mounted within a railway unit center sill assembly. The apparatus includes a cushioning housing having mechanical and hydraulic cushioning cavities and being operable for translation between buff and draft stop members within the sill structure. A mechanical cushioning assembly is positioned within the mechanical cushioning cavity and includes a high capacity of elastomeric cushioning pad. A follower abuts against the elastomeric pad and carries spacer arms which at least partially surround the elastomeric pad. The spacer arms have an axial extent less than the axial dimension of the cushioning unit, whereby the elastomeric pad is operable to accommodate compression between the follower and the cushioning housing until the spacer members go solid between the cushioning housing and the follower. A hydraulic cushioning assembly is positioned within the hydraulic cushioning cavity and includes a coaxial cylinder which divides the cushioning cavity into a high pressure inner chamber and a surrounding low pressure chamber. A piston is mounted for reciprocation within the interior of the high pressure chamber and port and valve means are provided to permit the flow of fluid from the high pressure fluid chamber with a first impedance in response to coupling force induced relative movement of the piston within the chamber and with a second greater impedance in response to run-in train action force induced relative movement of the piston within the chamber. A coupler bar extends within the draft end of the sill and is connected to the cushioning housing to impart buff and draft forces to the cushioning housing during coupling and train action events.

iUnite States Patent 1191 Stephenson et a1.

1451 Dec. 17, 1974 RAILWAY UNIT CUSHIONING APPARATUS [75] Inventors: Jack G. Stephenson; John E. Mosier,

both of Duncan, Okla.

[73] Assignee: Halliburton Company, Duncan,

Okla.

[22] Filed: Jan. 16, 1974 [21] Appl. N0.: 433,857

Related US. Application Data [63] Continuation-impart of Ser. No. 327,997, Jan. 30,

Primary E.raminerM. Henson Wood, Jr.

Assistan! Examiner-Gene A. Church Attorney, Agent, or Firm-Burns, Doane, Swecker & Mathis 5 7 ABSTRACT A cushioning apparatus operable to be mounted within a railway unit center sill assembly. The apparatus includes a cushioning housing having mechanical and hydraulic cushioning cavities and being operable for translation between buff and draft stop members within the sill structure. A mechanical cushioning assembly is positioned within the mechanical cushioning cavity and includes a high capacity of elastomeric cushioning pad. A follower abuts against the elastomeric pad and carries spacer arms which at least partially surround the elastomeric pad. The spacer arms have an axial extent less than the axial dimension of the cushioning unit, whereby the elastomeric pad is operable to accommodate compression between the follower and the cushioning housing until the spacer members go solid between the cushioning housing and the follower. A hydraulic cushioning assembly is positioned within the hydraulic cushioning cavity and includes a coaxial cylinder which divides the cushioning cavity into a high pressure inner chamber and a surrounding low pressure chamber. A piston is mounted for reciprocation within the interior of the high pressure chamber and port and valve means are provided to permit the flow of fluid from the high pressure fluid chamber with a first impedance in response to coupling force induced relative movement of the piston within the chamber and with a second greater impedance in response to run-in train action force induced relative movement of the piston within the chamber. A coupler bar extends within the draft end of the sill and is connected to the cushioning housing to impart buff and draft forces to the cushioning housing during coupling and train action events.

17 Claims, 16 Drawing Figures PATENTEL; BEE] 71974 3,854,533

SHEET 30F 5 PAIENTEU nun 1 I974 SHEET u BF 5 m m w "M p m FIG. 7

FIG. 6

RAILWAY UNIT CUSHIONING APPARATUS RELATED APPLICATION This application is a continuation-in-part of applicants copending U.S. application Ser. No. 327,997, filed Jan. 30, 1973, entitled Method and Apparatus for Providing Coupling, Train Action and Alignment Control for Railway Vehicles, and assigned to the assignee of the present application.

BACKGROUND OF THE INVENTION This invention relates to an apparatus for providing coupling, train action and alignment control for articulated vehicles. More particularly, the invention pertains to an apparatus for providing coupling, train action and alignment control for railway units, such as railway cars or locomotives.

Railway units, such as freight cars and the like, typically are provided with draft gear mechanisms in association with coupling devices. Such mechanisms enable shock forces, such as for example generated during marshaling of trains within a yard, to be absorbed and thus diminish the impact imparted to goods contained within railway units.

While conventional draft devices have provided at least a degree of coupling shock protection, there remained a substantial problem in coping with dynamic train action events.

in this connection train action events may be defined as a phenomenon which occurs as a consequence of the existence of slack in couplings between moving railway units. Such slack enables the units, in motion, to undergo relative movement. Thus train action denotes the equalization of the speed of adjacent units which have undergone relative movement. A train action event is termed a run-out where adjacent units are moving apart. Where adjacent units are converging, the train action event may be termed a run-in.

There are several undesirable aspects associated with train action phenomena. While train action is occurring crewmen experience an undesirable floating sensation. At the termination of train action events, shock forces are transmitted to the railway units. Often these shock forces are transmitted in a more or less wave form throughout a train. Such train action induced shock forces are often severe enough to both damage goods carred by a railway unit and cause injury to train crewmen. Indeed, train action induced shock forces may in some instances be severe enough to induce derailment.

The problems involved in coping with train action run-in events and coupling impact loads are particularly aggravating and seemingly mutually inconsistent from the standpoint of solution. The greatest forces ordinarily imposed upon a coupling are those encountered in a railway yard where trains are being marshalled and units moving at a relatively low speed abruptly engage for coupling purposes. In order to absorb the high level shock generated during such coupling operations, it is necessary that cushioning devices have a capacity to move relatively rapidly and dissipate large amounts of energy on a fairly uniform basis.

However, when a train is in motion and relatively low level forces are acting on the coupling units so as to tend to induce a run-in phenomenon, i.e., induced converging of coupling units, the requisites of the cushioning device necessary to absorb high level coupling shocks are self-defeating. In this connection when a coupling unit is designed to move rapidly enough to absorb coupling shock, its capacity to later impede slow coupling movement so as to control run-in is severely restricted.

Conversely, if the cushioning mechanism is designed to impede coupler movement to an extent sufficient to control run-in events, the cushioning device will be unusable to effectively absorb high energy coupling shocks.

A somewhat similar problem is occasioned in connection with coping with train action run-out events. In this connection it will be appreciated that during run-out it would be desirable to induce substantial impedance to separating motion of railway units and thus minimize train action phenomena during runout. However, it is also desirable to maintain a cushioning unit in a preferred mode which typically entails a posture ready to accommodate buff coupling forces. Therefore, it is desirable to provide a cushioning system with a resilient restoring mechanism to bias the coupling units in a preferred draft direction. During the restoring operation it will be appreciated that it is undesirable to substantially impede relative movement of the cushioning mechanism. Therefore, design considerations in terms of coping with run-out events and restoring the coupling units to a preferred posture are again self-defeating. v

For controlling train action phenomena, reference may be had to a Stephenson et al. U.S. Pat. No. 3,589,527 issued June 29, 197i and assigned to the assignee of the subject application. Notwithstanding, however, the merits of the cushioning assembly described in the above referenced Stephenson et al. patent and the singular contribution made thereby to the railway industry, room for improvement remains in coping with train action phenomena.

In this connection, even though hydraulic cushioning units, such as featured in the above references Stephenson et al. patent, are utilized high train action forces may yet develop under certain circumstances clue to terrain and/or the manner in which an engineman controls the locomotive.

More particularly, under terrain conditions which precipitate sustained run-in train action, such as might occur in traversing a lengthy descending grade or under conditions where an engineman may exclusively utilize locomotive dynamic or independent air brakes to reduce the speed of or stop a train, the hydraulic cushioning units after a period of time will glide to a fully closed posture at the extreme buff end of the hydraulic cushioning unit. Accordingly, the hydraulic cushioning units are no longer able to absorb energy. If this phenomenon occurs throughout a substantial block of cars, an engineman is faced with a solid mass of steel thirty or forty cars long, traveling along a railway track/Under these conditions a change in force caused by the impact of a car or a sudden change in engine throttle position, will be transmitted throughout the solid block of cars. The resultant high forces, in many instances are sufficient to break couplers, knuckles, and even cause derailment.

Accordingly it would be highly desirable to provide an apparatus for end of stroke cushioning which would not be time dependent and thus free from gently gliding solid under sustained run-in train action.

In addition to the foregoing outlined difficulties occasioned in coping with coupling and train action phenomena, railway units under conditions of pusher or sustained locomotive braking operations frequently assume a condition of misalignment. Such misalignment has a tendency to precipitate numerous deleterious effects, such as heated journal bearings hot boxes, spreading of railway rails and excessive wheel flange and/or rail head wear. Indeed in some instances of prolonged and severe misalignment the possibility of derailment again becomes a serious consideration.

At least one previously known alignment control assembly for railway vehicles is specifically disclosed in a Metzger U.S. Pat. No. 2,754,578, issued July 17, I956.

It has been found, however, that under sustained run-in" or braking operations wherein alignment control is most needed, conventional cushioning assemblies and draft gears may go solid and thus prevent realignment due to the inability of adjacent units to undergo relative separating motion.

It would therefore be highly desirable to provide, in combination with an alignment control assembly, a cushioning assembly which would be operable to accommodate and facilitate alignment control during normal train action run-in events and also during sustained run-in train action phenomena.

Under sustained run-in action, and as previously noted, alarge block of railway unit may essentially go solid, thus presenting a potential for the generation of tremendous forces in the event of an impact on a car or sudden change in engine throttle position. It would OBJECTS AND SUMMARY OF THE INVENTION PRINCIPAL OBJECTS OF THE INVENTION It is therefore a general object of the invention to provide a novel railway unit cushioning apparatus which will obviate or minimize problems of the type previously described.

It is a particular object of the invention to provide a novel cushioning apparatus for enhancing coupling train action and restoring control for railway units.

It is a further object of the invention to provide a novel railway unit cushioning apparatus operable to cushion coupling and train action forces under normal conditions and further provide effective cushioning under sustained train action operations.

It is still a further object of the invention to provide a novel railway unit cushioning apparatus operable for cushioning high level shock forces even after a sustained train action phenomenon.

It is yet a further object of the invention to provide a novel railway cushioning unit for combining in series hydraulic and mechanical cushioning units whereby cushioning in either buff or draft may be provided even after the hydraulic cushioning capability has been expended during a sustained train action event.

It is still yet a further object of the invention to provide a novel railway cushioning unit for combining in series a hydraulic cushioning unit and a highly precompressed elastomeric cushioning unit wherein stroking of the elastomeric unit is limited to extremely high forces.

It is another object of the invention to provide a novel method and apparatus for enhancing alignment control forrailway locomotive vehicles.

It is still another object of the invention to provide a novel railway unit cushioning apparatus for enhancing alignment control of railway units even during sustained run-in train action events.

It is yet another object of the invention to provide a novel railway unit cushioning apparatus for combining in series hydraulic and mechanical cushioning units both of which are operable in the buff and draft directions and wherein the possibility of overtravel of either the mechanical or hydraulic units in either direction is eliminated.

BRIEF SUMMARY OF THE INVENTION A railway unit cushioning apparatus, according to a preferred embodiment of the invention and intended to accomplish at least some of the foregoing objects, is operable to be inserted within a still assembly directly connectable to and longitudinally aligned with the underframe of a railway unit. The sill assembly includes a first side wall normally projecting downwardly from the underframe of the railway unit and a second side wall projecting downwardly from the underframe of the railway unit and extending in a spaced parallel posture coextensively with the first side wall. An anchor and buff backstop housing is positioned between the first and second side walls at the buff end of the sill and stop lugs are connected within the sill side walls at the draft end of the sill assembly.

A coupling bar having a shank portion is extended into the draft end of the sill and is pinned or keyed to a mechanical and hydraulic cushioning housing which operatively translates between the buff backstop and the draft stop. i

The cushioning housing is fashioned with a transverse barrier which defines on a draft side thereof a mechanical cushioning cavity at the draft end of the housing and on the buff side thereof a hydraulic cushioning cavity at the buff end of the housing. The mechanical cushioning cavity is further defined byinwardly extending retainer means at the draft end of the cushioning housing. The hydraulic cushioning cavity is further defined by a wall transversely extending across the buff end of the cushioning housing.

A mechanical cushioning assembly is positioned within the mechanical cushioning cavity and includes a follower which abuts against a preferably solid rectangular elastomeric cushioning member which in turn is mounted against the transverse barrier. Spacer arms extend from the follower and at least partially surround the cushioning unit. These spacer arms have a longitudinal dimension less than the longitudinal extent of the elastomeric cushion whereby the cushion may be compressed until the follower goes solid with the transverse barrier through the spacer arms.

Hydraulic cushioning is provided by a cylinder coaxially extending within the hydraulic cushioning cavity' between the transverse barrier and an end wall to form a high pressure inner cylinder and a low pressure outer cylinder with the housing wall. A piston is mounted for translation within the high pressure cylinder and is connected to a piston rod which extends throughthe end wall to an anchor within the buff backstop housing assembly. Valve passages are provided at either end of the high pressure fluid cavity for permitting relatively unobstructed flow of fluid from the low pressure fluid cavity into the high pressure fluid cavity, while resisting fluid flow from the high pressure fluid cavity into the low pressure cavity. The high pressure cylinder is fashioned with a plurality of ports which permit flow from the high pressure fluid cavity into the low pressure fluid cavity with a first impedance in response to coupling force induced relative movement of the piston within the cylinder and with a second impedance greater than the first impedance in response to run-in train action force induced relative movement of the piston within the cylinder.

The previously noted coupler bar extending within the railway sill is pinned or keyed to the cushioning housing and is operable in response to buff forces to transmit compressive forces through the mechanical cushioning assembly and into the cushioning housing to effect actuation of the hydraulic cushioning assembly until the hydraulic cushioning assembly goes sold through the high pressure cylinder with the buff backstop member. The coupler bar is further operable to transmit buff forces into the mechanical cushioning assembly to effect compression of the elastomeric cushioning pad until the spacer arms go solid with the transverse barrier of the cushioning housing member.

The coupler bar is further operable in response to draft forces to transmit the draft forces into the cushioning housing and effect actuation of the hydraulic cushioning unit until the follower plate of the mechanical cushioning assembly abuts the draft stops. Further draft forces are imparted into the mechanical cushioning assembly to effect compression of the elastometic cushioning pads until the spacer arms go solid with the transverse barrier of the cushioning housing means.

The elastomeric cushioning assembly is preferably precompressed to a value of at least 50,000 lbs. by inserting of spacer bars between the follower plate and the'inwardly projecting retainer means. Thus normal train action forces will be transmitted through the me chanical unit into the hydraulic cushion unit without stroking the mechanical cushioning unit. Elastomeric cushion cycling is thus minimized which increases the life of the elastomeric unit. Further, high level precompression insures cushioning control which is not time dependent and which is operable to cope with high level forces which may be imparted to the cushioning assembly.

In some instances the follower plate of the mechanical cushioning unit and the buff end of the coupler bar are fitted with alignment control mechanisms. This alignmentcontrol in combination with the hydraulic and mechanical cushioning assembly, as previously noted, facilitates alignment control under normal rain action events and also during sustained run-in" train action phenomena by providing at least a degree of Iongitudinal movement of the coupler bar.

THE DRAWINGS Further objects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view of a portion of the underframe of a railway unit and components of a mechanical and hydraulic cushioning apparatus with the components disclosed in an exploded or separated format;

FIG. 2, note sheet 2, is a cross-sectional view ofa railway unit mechanical and hydraulic cushioning apparatus according to a preferred embodiment of the invention in a full buff posture within a railway unit underframe sill;

FIG. 3 is a cross-sectional view of a mechanical and hydraulic cushioning apparatus, such as disclosed in FIG. 2, but positioned in a full draft posture within an underframe sill structure;

FIG. 4, note sheet 3, is a cross-sectional view taken along second line 4-4 in FIG. 2 and discloses a mechanical cushioning unit in a full buff posture;

FIG. 5 is a cross-sectional detailed view taken along section line 5-5 in FIG. 3 and discloses a mechanical cushioning unit in a full draft posture;

FIG. 6 is a cross-sectional view taken along section line 6-6 in FIG. 2 and discloses an inner high pressure fluid chamber and an outer surrounding relatively low pressure fluid chamber, with coupling and run-in valves mounted upon the wall of an inner high pressure fluid cylinder;

FIG. 7 is a cross-sectional view taken along section line 7-7 in FIG. 2 and discloses a run-out valve mounted upon the wall of the inner high pressure fluid cylinder;

FIG. 8, note sheet 1, discloses an enlarged, transversely sectioned, view of a check valve mechanism as mounted at the buff end of the inner cylinder of the hydraulic-cushioning unit and permits hydraulic fluid to flow from the low pressure fluid chamber to the high pressure fluid chamber;

FIG. 9, note sheet 4, provides a plan view of an inner cylinder wall of the hydraulic cushioning apparatus which is longitudinally severed and laid flat for ease of illustration;

FIG. 10, note sheet 5, provides an enlarged, elevational and sectional view of a valve mechanism operable to control fluid to flow through at least a portion of a plurality of ports fashioned through the high pressure cylinder wall with the valve components in a relaxed or normal condition, i.e., with no fluid forces acting upon the components;

FIG. 11 illustrates the components of the FIG. 10 valve assembly as the components are disposed during an outflow of fluid from the inner cylinder of the hydraulic cushioning mechanism so as to control run-in train action events;

FIG. 12 illustrates the components of the FIG. 10 assembly as the components are disposed during an outflow of fluid from the inner high pressure cylinder of the hydraulic cushioning unit in response to coupling shock forces on the coupling member;

FIG. 13 is a transverse cross-sectional view taken along section line 13-l3 in FIG. 10;

FIG. 14 is a transverse cross-sectional view taken along section line l4l4 in FIG. 10;

FIG. 15 is a cross-sectional view taken along section line l5-l5 in FIG. 10; and

FIG. 16, note sheet 1, is an enlarged, transversely sectioned, view of a valve mechanism mounted at the draft end of an inner hydraulic cylinder of the hydraulic cushioning unit which serves to control run-out train action events.

DETAILED DESCRIPTION PRINCIPAL COMPONENTS With reference now to the drawings and particularly to FIGS. 1 through 3 thereof there will be seen various views of a railway cushioning apparatus according to a preferred embodiment of the invention.

More specifically, a sill structure 100 is fixedly mounted upon an underframe 102 of a railway unit such as a railway car or locomotive. The sill structure 100 is fashioned with a first side wall 104 generally downwardly extending with respect to the railway unit underframe 102 and a second side wall 106 which also extends downwardly from the railway unit underframe 102 and in a spaced-parallel posture coextensively with respect to the first side wall 104. The sill side walls 104 and 106 are flared at one end of the sill structure 100 as at 108 to accommodate swinging movement of a coupler bar mounted within the sill. The outwardly projecting or draft end of the sill structure 100 is enclosed with a generally rectangular striker plate 110.

An anchor and buff backstop unit 112 is mounted within a buff end of the sill structure 100 and includes an anchor cavity 113 and a longitudinally extending buff backstop housing 114. The anchor and buff backstop unit is preferably securely welded within the sill 100 to eliminate any possibility of longitudinal draft or displacement of the unit 112 within the sill. Draft stop plates 116 and 118 are mounted upon the sill side walls 104 and 106 generally at the draft end thereof as at flared locations 108.

A mechanical and hydraulic cushioning unit 120 comprising the principal component of the subject invention, is mounted for translation and sliding contact with the sill side walls 104 and 106 in response to coupling and train action forces imparted thereto. Movement of the cushioning unit 120 in the buff direction is limited by buff backstop housing 114, while movement of the cushioning unit 120 in the draft direction is limited by draft stops 116 and 118.

The cushioning unit 120 includes an outer cushioning housing 122 forming a mechanical cushioning cavity 124 generally at a draft end thereof and a hydraulic cushioning cavity 126 generally at a buff end thereof.

Positioned within the mechanical cushioning cavity 124 is a mechanical cushioning and alignment assembly 128 which will be discussed in detail hereinafter. Positioned within the hydraulic cushioning cavity 126 is a hydraulic cushioning assembly 130 which will also be discussed in detail hereinafter.

The mechanical and hydraulic cushioning housing 122, as previously noted, is operably positioned between the sill side walls 104 and 106 and is supported for translation therein upon a generally U-shaped sill base plate 132. The base plate is preferably connected to the parallel sill side walls 104 and 106 by conventional threaded fasteners for ready installation and removal of the cushioning unit 120.

The hydraulic cushion assembly 130, includes a piston rod 134 which operatively projects toward and is anchored within cavity 113.

In this connection, the distal end of piston rod 134 is connected to an anchor assembly 136 which serves to alleviate nonaxially directed load. An anchor assembly of this type is described, for example, in the previously noted Stephenson et al. U.S. Pat. No. 3,589,527. The

relevant disclosure of this patent, and particularly FIG. 15, and the associated discussion is hereby incorporated by reference. For the present purpose, however, it is sufficient to note that this anchor assembly 136 includes a headlike portion 137 having arcuate generally spherical segment surfaces 138 and 139. A bearing plate 140 conformingly engages surfaces 138 while a similar bearing plate 142 engages surfaces 139. Plates 140 and 142 are interconnected and mounted within housing cavity 113 through the provision of a securing or retainer plate 144.

A restoring mechanism 148 provides a resilient interconnection between the sill 100 and a tongue 150 downwardly projecting from a draft end of the mechanical and hydraulic cushioning unit 120. The restoring mechanism 148 is typically fabricated from a plurality of coil springs 152 and serves to yieldably and resiliently bais the mechanical and hydraulic cushioning housing 122 toward a draft end of the center sill structure 100. Restoring mechanism 148 may be of the general type described, for example, in Abbot et al. US.

. Pat. No. 3,233,747 issued Feb. 8, I966 and assigned to the assignee of this application.

Once the mechanical and hydraulic cushioning unit 120 is mounted within the center sill a coupler bar or shank 154 is inserted through the striker plate and coupled to a draft end of the housing 122 through the provision of a coupler pin 156. Once assembled the coupler pin may be retained within the housing 122 by a threaded plug 157 received within tongue 150, note FIGS. 4 and 5.

MECHANICAL CUSHIONING AND ALIGNMENT CONTROL ASSEMBLY ioned with a transversely extending barrier or wall and inwardly projecting retainer legs 162 and 164. The follower plate 158 normally lies in a plane generally parallel with the barrier 160 and retainer legs 162 and 164 and operatively is mounted for longitudinal translation with respect thereto.

The mechanical cushioning unit 128 further includes a cushioning pad 166 which is preferably composed of a solid elastomeric unit having a rectangular cross section. While a solid rectangular shape is preferred other configurations are contemplated such as pads having internal voids and/or sculptured edges.

The elastomeric pad 166 is faced with metallic plates 168 and 170. Plate 168 is dimensioned to be received within a depression 172 fashioned within the follower plate 158 while complemental plate is received within a depression 174 fashioned within the barrier wall 160.

The elastomeric unit 166 is at least partially surrounded by upper and lower spacer legs 176 and 178 which longitudinally extend in a buff direction from the follower plate 158. The spacer legs 176 and 178 are longitudinally dimensioned to be less than the unstressed thickness of the elastomeric pad 166. The elastomeric pad may thus be compressed between the follower plate 158 and the barrier wall 160 until the spacer legs 176 and 178 go solid with the transverse barrier 160. Further compression of the elastomeric member is prevented thus eliminating the possibility of over compression and destruction of the elastomeric pad under extremely high compressive forces.

The mechanical cushioning assembly 128 is operable to resiliently cushion both buff and draft forces imparted to the coupler bar 154. More particularly, in buff the coupler bar 154 moves from left to right as viewed in FIGS. 2 and 4 and abuts against an alignment and bearing plate 180 which will be discussed more fully hereinafter. Compressive forces are transmitted directly through the bearing plate 180 into the follower plate which tends to compress the elastomeric pad 166 against the transversely extending barrier 160 of the housing assembly 122.

Full buff movement is disclosed in FIGS. 2 and 4 wherein the spacer members 176 and 178 have gone solid against the transverse barrier 160.

In draft, note FIGS. 3 and 5, the coupler bar 154 extends outwardly with respect to the sill 100 and functions to pull the mechanical and hydraulic cushioning housing 122 in a draft direction through the provision of the coupling pin 156. This movement is accommodated until the follower plate 158 abuts against draft stop members 116 and 118, note FIG. 3. Further movement of the housing 122 in the draft direction will serve to resiliently compress the elastomeric member 166 by the provision of a transverse barrier 160 compressing the elastomeric member against the immovable follower plate 158 which has gone solid against draft stops 116 and 118.

Elastomeric compression is accommodated as outlined above until the transverse barrier 160 goes solid with the spacer legs 176 and 178 whereupon further draft movement will be prevented. This posture of the mechanical cushioning assembly is depicted in FIGS. 3 and wherein full draft movement of the assembly is disclosed. I

In many instances of coupler'cushioning, such as during sustained run-in train action events or during sustained locomotive braking, it would be desirable to insure reserve cushioning which would not be time dependent. In this regard hydraulic cushioning units, to be discussed in detail hereinafter, inherently possess a disadvantage of running solid even under small loads if the loads are imparted over a substantial time frame. When such loads are occasioned thirty or forty cars may go solid with respect to hydraulic cushioning capability.

The subject invention obviates this disadvantage by the provision of the elastomeric pad 166. In order to insure, however, high load capacity and to minimize wear of the elastomeric pad due to excessive stroking under small loads the pad is highly precompressed.

More particularly after the cushioning assembly 128 is inserted'within cavity 124 upper and lower high compression spacers, rods or bars 181 are inserted between the retainer legs 162 and 164 and the follower plate 158 to precompress the elastomeric pad 166.

The thickness of rods 181 determines the extent of precompression and in accordance with the subject invention the rods are dimensioned to precompress the elastomeric pad at least with fifty thousand pounds of force. Accordingly for coupler forces of less than fifty thousand pounds the elastomeric pad will remain uncompressed and thus will be operable to provide resilient cushioning for extreme forces in a manner to be discussed more fully hereinafter.

Alignment Control Assembly In order to minimize the possibility of adjacent units from becoming misaligned it may be desirable to provide an alignment control assembly which may be advantageously combined with the mechanical and hydraulic cushioning of the subject invention. The concept and basic operating structure of an alignment control assembly is disclosed in a Metzger US. Pat. No. 2,754,578 issued July 17, 1956. Reference may be had to this United States Patent for an understanding of the functioning and theory of operation of an alignment control assembly.

Structurally the alignment control assembly of the subject invention in combination with a mechanical and hydraulic cushioning unit includes alignment shoulders 182 and 184 positioned upon lateral portions of the coupler 154 at the butt end thereof, note FIG. 3.

The bearing plate is fashioned with a concave central recess 186 which is compatibly dimensioned with a convex exterior surface 188 at the butt end of the coupler bar 154. Concave surface 186 is operable to receive in intimate contact the convex butt end of the coupler 188 through an arc of coupler shank travel.

The concave recession 186 is flanked on the lateral sides thereof by first and second concave surfaces 190 and 192. These concave surfaces serve to intimately receive compatible arcuate convex surfaces 194 and 196 fashioned upon the alignment shoulders 182 and 184 respectively. 7

Excessive counterclockwise swinging movement, n'ote FIG. 2, of the coupler bar 154, will serve to bring alignment shoulder surface 194 into abutting engagement with bearing pad concave surface 190. Further swinging counterclockwise will be structurally prevented and in fact a righting couple will be created as more fully disclosed in the previously mentioned United States Metzger patent to realign the coupler bar 154 into generally longitudinal alignment with the railway unit center sill 100.

The foregoing alignment capability is uniquely enhanced by the subject invention through the combined hydraulic cushioning unit and high compression mechanical cushioning assembly which are mounted in series with the bearing and alignment pad 180. More particularly the hydraulic cushioning unit serves to cushion coupling and train-action forces and provide longitudinal movement of the coupler bar which facilitates alignment control. Under sustained loading conditions, when hydraulic cushioning may be spent, the precompressed elastomeric cushioning unit provides yet further longitudinal movement capability in response to high level forces to facilitate alignment of the railway units.

FLUID IMPEDANCE SYSTEM General Structure Referring now particularly to FIGS. 2, '3, 6 and 7, it will be seen that the buff end of the mechanical and hydraulic cushioning housing 122 is interiorly fashioned with a hydraulic cushioning cavity 126 for the reception of an interior coaxially extending relatively high pressure cylinder 200.

The high pressure cylinder 200 is generally circular in cross-section, note FIGS. 6 and 7, and is peripherally surrounded by an outer wall 202 having a generally rectangular cross-section which comprises a portion of the housing structure 122.

The interior cylinder is designed to accommodate relatively high pressures, in a manner which will be discussed hereinafter, and is accordingly fashioned with a radial thickness several magnitudes greater than the thickness of the outer wall 202.

The cylinder walls 200 and 202 extend at a buff end thereof against the buff side of the transversely extending barrier 160 of housing 123. At the draft end the inner and outer cylinder walls 200 and 202 are closed by a normally extending end wall 204. The inner and outer cylinders are welded at each end to the end walls to form within the hydraulic cushioning cavity 126 an inner high pressure fluid cavity 206 and an outer relatively lower pressure fluid cavity 208.

A piston head 210 is mounted for reciprocation within the interior of the high pressure cylindrical cavity 206. The piston 210 is provided with at least one peripheral sealing gland 212 which intimately wipes against the interior surface of the high pressure cylinder wall 200 as the cylinder is reciprocated in response to buff and draft forces.

A piston rod 134 is projected through an aperture 214 within the end wall 204 and is fixedly connected to the draft side of the piston head 210. The piston rod 134 extends through a suitable peripheral chevron packing assembly 216 and is anchored within buff backstop and anchor assembly 112 as previously discussed.

An accordian-like elastomeric dust shield 218 is connected at one end to the cylinder end wall 204 and at the other end to the piston rod 134. This dust shield structure protects the portion of the piston rod 134 which reciprocates into and out of the high pressure cylinder 200.

In order to provide fluid communication from the low pressure cavity 208 to the high pressure cavity 206 at the draft end of the hydraulic unit a plurality of high volume flow passages 220 are formed through the end wall 204. A check valve ring 222 is disposed about the interior surface of the end wall 204 to provide one way fluid communication between the low and high pres: sure cavities.

The structure and mode of operation of this check valve ring is described in detail, for example, in Blake US. Pat. No. 2,944,681 issued July 12, 1960, assigned to the assignee of the present application. The relevant portion of this Blake patent is hereby incorporated by reference. For present purposes, however, it is sufficient-to note that by the provision of check valve ring 222 fluid is free to flow from the low pressure fluid cavity 208 into the high pressure fluid cavity 206 while the fluid within the high pressure fluid cavity 206 will be prevented from flowing past the check valve ring into the low pressure fluid cavity 208.

In a similar vein, a check valve 224 is mounted at the buff end of the high pressure cylinder 200 and serves to provide fluid communication from the low pressure cavity 208 into the high pressure fluid cavity 206.

More specifically, the check valve assembly 224, note FIG. 8, provides continuous controlled communication between the low pressure fluid cavity 208 and the high pressure fluid cavity 206 through'a port 226. The flow capacity of the port 226 is of a relatively high magnitude so as to afford minimal resistance to return flow of fluid from the low pressure fluid cavity 208 into the high pressure fluid cavity 206.

The check valve mechanism 224 comprises a body 228 connected by threaded coupling means 230 to the high pressure cylinder wall 200. A valve member 232 is telescopingly mounted within the valve body 228. The valve member 232 is generally cylindrical in character and includes a cylindrical side wall 234 provided with a plurality of radial ports 236. An imperferate head wall 240, connected with side wall 234, provides a sealing surface 242 to sealingly engage a valve seat 243 formed on valve body 228. A coil spring 244 interposed between valve member carried abutment 246 and a valve body carried abutment 248 serves to yieldably bias the valve member 232 in a closed position.

In response to relatively low pressure in cavity 206, resulting from draft movement of the high pressure cylinder 200, the valve 232 will automatically open so as to allow a return flow of fluid from the low pressure cavity 208 into the high pressure cavity 206.

Run-In and Coupling Shock Control In order to cushion relative movement of the mechanical and hydraulic cushioning housing 122 within the sill a plurality of metering ports 250 through 272 are fashioned through the high pressure cylinder wall 200, note FIGS. 2, 3 and 9. The plurality of ports 250 through 272 are aligned for ease of illustration in F I68. 2 and 3 with increasing exponential spacing from the buff to the draft end of the high pressure cylinder 200.

The spacing of ports 250 through 272 is more accurately illustrated in FIG. 9 wherein high pressure cylinder wall 200 is separated at a median and longitudinally extending line 274, and laid flat. Line 274 represents the intersection of the longitudinally extending vertical median plane passing through the high pressure cylinder 200. The exponential spacing concept herein referred to corresponds to that described, for example, in

Seay US. Pat. No. 3,301,410, issued Jan. 31, 1967, and assigned to the assignee of the subject invention. In this connection, with the metering orifices spaced exponentially, kinetic energy is absorbed uniformly throughout the stroke of the apparatus, thus pressure within the working cylinder and the force applied to the apparatus approach uniform and minimum values throughout the stroke. Asa result, minimum accelerations are imparted to the system cushioned by the apparatus.

In one embodiment of the invention, where the piston 210 is operable to reciprocate longitudinally within cavity 206 through an increment of about 15 inches, and where the inner diameter of cylinder wall 200 is approximately 8 inches, and where piston rod 134 has a diameter of approximately 3% inches, the exponentially spaced ports 250 through 272 are spaced from the cylinder end 276, in a direction measured longitudinally or parallel to the junction 274, in general accordance with the following tabulation:

Distance in inches from -Continued Distance in inches from All of the ports 250 through 272, in the embodiment characterized by the dimension above-noted, are of the same diameter, i.e., nineteen sixty-fourths inches.

In this embodiment the longitudinal width of the piston 210, i.e., the distance between piston sides is approximately 2 /z inches.

In the full buff position of piston 210, this piston covers ports 250 through 260. Each of these six ports adjacent cylinder end 276 are individually controlled by a control valve 300 while ports 262 through 272 are continuously open and unvalved.

Run-In Control In order to provide a first impedance through the ports 250 through 260 when coupling buff forces are encountered and a second high level impedance in ports 250 through 260 when train action run-in forces are encountered each of the ports 250 through 260 is preferably fitted as previously noted with a control valve 300 such as schematically illustrated in FIG. 9 and specifically illustrated in FIGS. 10 through 15. Control valve 300 is substantially the same as the run-in control valve described in Stephenson US. Pat. No. 3,589,528 issued Aug. 14, 1968 assigned to the assignee of the subject application. The disclosure of this Stephenson patent is hereby incorporated by reference as though set forth at length.

For the present purposes, however, the basic structure and functioning of the control valve 300 comprises a generally cylindrical body 302. A threaded coupling 304 serves to threadedly secure the valve 300 to the exterior of the wall 200 in a radially extending alignment with respect to the central axis of the high pressure cylinder and in coaxial disposition with an associated port. The valve 300 illustrated in FIGS. 10 through is shown in association with any one of the fluid ports in the exponential series 250 through 260.

As shown in FIG. 6 the various valves 300 are arranged so as to project into the enlarged portions of the cavity 208, where maximum space is available.

Returning to the basic structure of valve 300, each valve includes a reciprocable, generally cylindrical, spool valve member 306. Each such spool valve member includes a generally cylindrical body portion 308 having a closed, radially outermost, extremity 310. A plurality of radially extending ports 312 intersect the cylindrical wall portion 308, immediately beneath the end wall 310. In the embodiment characterized by the dimensions above-noted, four ports 312 are provided.

The end 314 of valve 306, facing the central axis of the high pressure cylinder, is open as shown in FIG. 10.

Each reciprocable valve further includes a generally annular rimlike piston 316 which may be tenned, or included in the term valve closing means". This piston extends radially outwardly from cylinder wall 308, generally adjacent the free end 314.

An annular shoulder or ledge 320 is formed on the outer periphery of cylindrical wall 308. Ledge 320 faces generally axially, toward the head portion 310 of valve 306.

A valve body cap 322 closes the outermost end of the valve body 302, and telescopingly receives the cylindrical wall 308. As illustrated, closure cap 322 may be disclike in structure. Closure 322 is provided with a central aperture 324 through which cylindrical wall portion 308 reciprocates.

Closure 322 provides an annular abutment 326 extending radially outwardly from a cylindrical cap surface 328, which surface defines aperture 324. With abutment 320 engaged with abutment 326, the main valve ports 312 are positioned so as to clear, i.e., be spaced outwardly from, the outer extremity 330 of closure 322.

Valve 300 is biased outwardly of the central axis of the high pressure cylinder so as to bring the abutment 320 into engagement with abutment 326 by a coil spring 332. This spring 332 abuttingly engages an annular recess or seat 334 formed in the free end 314 of the valve wall 308.

As shown in FIG. 10, closure 322 cooperates with a radially extending valve body wall 336 and a cylindrical body wall 338 to define a generally annular cylinderlike cavity 340. Valve piston 316 is operable to reciprocate through cavity 340.

Port means 318 provide, by way of port P, fluid communication between the high pressure cavity and the zone 341 of cavity 340 which is disposed between the closure 322 and the piston 316.

A plurality of ports 342 intersect the generally hexagonal base wall 344 of valve body 302, immediately adjacent, but radially outwardly of, the cylinder end wall 336. Port means 342 thus serve to provide fluid communication between the low pressure cavity 208 and the portion 343 of cylinder cavity 340 disposed between piston 316 and valve body wall 336.

Thus, piston 316 is biased inwardly toward the central axis of the high pressure cylinder by the pressure of fluid within the cavity 206. Piston 316 is biased radially outwardly, away from the central axis of the low pressure cylinder means by a generally low pressure fluid within cavity 206.

Thus, when the higher pressure of fluid within cavity 206, acting through port means 318 on piston 316, overcomes both the spring biasing of spring 332, and the fluid pressure of cavity 208 transmitted through ports 342 to piston 316, the valve 302 will move radially inwardly to a closed valve position, i.e., the position shown in FIG. 1. In this closed valve position, the ports 312 are covered and substantially closed by surface 328. Surface 328 is disposed in generally telescoping and conforming relation with the outer periphery 346 of valve wall 308.

In this connection, however, it will be understood that the relationship between outer periphery 346 of valve 306 and surface 328 may not be such as to provide complete sealing, i.e., some limited leakage may take place. Indeed, with the valve disposed in the FIG. 11 position, a degree of leakage through the valve takes place which is on the order of one-tenth of the flow permitted by the valve in the open position shown in FIG. 10.

lt will here be understood that the reaction surface 317 provided by the piston 316 in the zone 341 is suffcient to provide a net downward biasing operable to overcome both the biasing influence of spring 332, the biasing of fluid pressure in the zone 343, and any biasing acting outwardly on the valve 306 as a result of a restricted flow through the ports 312.

The restoring or biasing force of spring 332 is of a relatively low magnitude such that the valve member 302 will move to the closed valve position during any runin train action phenomena. This results because the low velocity of piston 200 during run-in events is sufficient to generate enough pressure in cavity 206 and cavity 341 to induce closing movement of valve 306. Coupling Control Valve mechanism 300 includes a unique disabling device 350 which serves to maintain the valve 302 in an open position when the coupler bar 154 is subjected to impact forces of the type encountered during coupling operations. Such operations ordinarily occur in railway yards where trains are being assembled and one car is moved into engagement with another with sufficient force to induce interlatching of the coupler bars of the two cars involved.

Because of the severity of such coupler forces, it is highly desirable to maintain an immediately effective low level of impedance in the coupling unit operable to dissipate impact energy in a generally uniform manner and without excessively stressing the cylinder components of the mechanism. This low level of impedance is in contrast to the high level of impedance previously described which is attained during run-in phenomena. The high level of impedance during run-in" phenomena is necessary in order to impede coupler movements where the level of forces acting on the coupler units is relatively low in comparison to those encountered during coupling operations.

The low level of impedance effected by the valve mechanism 300 will now be described with relation to FIGS. and 12.

Disabling mechanism 350 comprises a sleeve 352 mounted for telescoping movement within the valve member 306. As shown, sleeve 352 is generally cylindrical in configuration and has an open upper end 354 as well as an open lower end 356. Ends 354 and 356 are connected by a relatively thin walled, or recessed, cylindrical wall portion 358.

Upper end 354 is telescopingly and slidably supported by cylindrical wall portion 360 of valve 306. The lower end 356 of sleeve 352 is telescopingly and slidably supported by a cylindrical wall portion 362 formed in the valve body 302.

Sleeve 352 is provided with a radially outwardly extending ledgelike flange 364. Flange 364 defines an abutment which engages the end 366 of coil spring 332, i.e., the end of this spring opposite to the end 368 which is engaged by the seat 334.

In the normal or neutral position of valve 300 shown in FIG. 10, the spring 332 biases the flange 364 radially inwardly toward the axis of cylinder means 168 so as to cause the flange 364 to abuttingly engage an annular seat 370 formed in the valve body 302. With the flange 364 engaged with the seat 370 the spring 332 is operable to resist radially inward movement of the valve member 306.

The biasing effect of spring 332, both with respect to sleeve 352 and valve member 306 may be varied by selecting a spring 332 of appropriate resilience. This biasing effect may also be varied in accordance with the degree of spring prestressing which is dependent upon the distance between the seat 334 and the ledge 364, when this ledge is engaged with the abutment 370.

When the coupler bar 154 is subjected to coupling forces or impacts, there will be a tendency for the piston 210 to move relatively rapidly within the cylinder cavity 206. This tendency to undergo rapid movement will generate a high pressure within the high pressure cavity 206 and tend to induce a relatively high-velocity fluid flow, radially outwardly through the central passage 374 of the sleeve 352. This fluid flow, because of its relatively high velocity, will produce a substantial pressure drop longitudinally across the sleeve 352. This pressure drop will overcome the biasing influence of the spring 332 and cause the sleeve 352 to move radially outwardly with respect to the longitudinal axis of the high pressure cylinder 200.

The outward movement of sleeve 352 will terminate when the outermost sleeve end 354 engages an annular abutment 376 formed in valve member 306. Abutment 376 comprises a generally radially extending wall projecting outwardly from a cylindrical wall 378. Cylindrical wall 378, in essence, defines the inner surface of wall 308.

With the sleeve end 354 engaged with the abutment 376, this sleeve end 354 is operable to close the ports 318, i.e., substantially isolate piston 316 from fluid flowing through passage means P as shown in FIG. 12. With the ports 318 thus closed, the ability of the piston 316 to move the valve member 306 to a closed valve position is obviated.

Sleeve 352 is characterized by'a substantially lower inertia factor than that possessed by the valve 306. This difference in inertia will tend to cause the sleeve 352 to move relatively rapidly to the FIG. 12 position, before fluid pressure is able to build up in the zone 341 and induce movement of the piston 316. Further, a high velocity flow through the passage 380 and through the central passage of the valve member 308, will tend to create a velocity reaction force acting on the valve head 310 so as to tend to hold the valve member 306 in its open position while the sleeve 352 is moving to its disabling position.

Once the valve 308 has moved to a closed valve position, it is unlikely that the sleeve 352 will be able to move radially outwardly to close the ports 318 so as to obviate the biasing influence of piston 316. The closing of ports 312 will probably prevent a flow of sufficient velocity through the passage 380 to induce movement of the sleeve 352. This valve characteristic, however, is not believed to be of adverse consequence because during run-in phenomena, train action forces would not be expected to approach the magnitude of coupling forces so as to require that the ports 312 remain open.

in the system here described, it is contemplated that each of the valves 300 will be of identical configuration and operating characteristics. Thus, during run-in phenomena, each of the valves 300 associated individually with the ports 250 through 260 should close more or less simultaneously, in response to run-in phenomena.

However, it is recognized that under certain conditions it may be desirable to provide valves 300 which operate in sequence or at different times so as to provide progressive closing off or constricting of the ports.

It will also be recognized that the number of ports required to control run-in phenomena may vary, depending upon operating conditions, and that the number of these ports which are valved may vary, depending upon operating criteria.

Run-Out and Restoring Control System In order to provide a high impedance to draft forces occasioned by run-out train action events, and yet simultaneously permit and facilitate restoring of the piston head 210 to the draft end of the high pressure cylinder 200 by the restoring assembly 148, the high pressure cylinder porting system includes a relatively small capacity port 398 and a somewhat larger capacity port 400, provided with a control valve mechanism 402.

Control valve 402 is substantially the same as the run-out control valve described in detail in Stephenson et al. US. Pat. No. 3,451,561 issued June 24, 1969 assigned to the assignee of the instant application. The disclosure of this Stephenson et al patent is hereby incorporated by reference as though set forth at length.

In summary, control valve 402, note FIG. 16, sheet I, is characterized by a generally cylindrical valve body 404. Valve body 404 is attached by threaded fastening means 406 to wall 200. When thus attached, valve body 404 extends generally coaxial of port 400, i.e., radially of the central axis of cylinder 200.

Control valve 402 includes a generally cylindrical valve member 408 mounted for telescoping movement within valve body 404. A coil spring 410, interposed between a valve body ledge 412 and a flange 414 carried by valve 408, serves to bias the valve member 408 radially inwardly with respect to the cylinder means 200. Inward movement of valve member 408 is limited by engagement of the flange 414 with a valve body ledge 416.

Valve member 408 is defined by a cylindrical wall 418 having an open upper end 420 and a closed lower end 422. One or more ports 424 intersect cylindrical wall 418 immediately adjacent the closed end 422.

With the valve 408 disposed in the neutral position shown in FIG. 16, the flow controlling port means 424 are disposed in communicating relation with the cavity 206. When the valve member 408 is moved radially outwardly, by overcoming the biasing influence of spring 410, a cylindrical wall 426 of valve body 404 valves-off" or closes the port means 424.

During run-in train action phenomena, fluid flowing from the cavity 206 through the port means 424, and thence through the valve passage 428, to the low pressure zone 208 will induce, i.e., insure or maintain, a substantial pressure drop across the closed valve head 442. This pressure differential may also be viewed as resulting, at least in part, from the difference in pressure between the zone 206 and the zone 208, resulting from movement of piston 210.

Regardless of the manner in which the pressure differential is explained, its existence will serve to induce radially outwardly movement of the valve 408 in response to run-out train action phenomena. This valve closing action will close off the port means, and thus provide a relatively high level of impedance operating against the piston 210 during run-out train action events.

It will also be appreciated that during run-out train action phenomena, once the piston means 210 has moved relative to the cylinder wall 200, so as to have cleared the series of exponential ports 250 through 272, and abrupt intensification of impedance will result because of the highly constricted nature of the port 398 and the closing of the port 400 by the valve 402. This impedance is further intensified when the piston 210 has moved relative to the cylinder wall 200 so as to have moved past the port 398. Once the port 398 has been cleared, virtually the only flow out of the cavity 206 will be effected by leakage through the closed valve 402, by leakage around piston 210 and by other highly constricted leakage paths.

When restoring spring assembly 14, however, tends to move the cylinder 200 in a draft direction, i.e., restore the unit from a buff condition, the pressure differential acting across the valve 408 will not be sufficient to overcome the biasing influence of the spring 410. Thus, the valve 402 will remain open during the restoring action so as to provide a relatively low level of impedance operating against the piston 210 during this restoring action. This relatively low level of impedance will tend to ensure that the spring assembly 148 is operable to effect rapid restoration of the cylinder to a preselected neutral position.

OVERALL MODE OF OPERATION OF COUPLING ASSEMBLY During a coupling action where high level buff shock forces are imparted to the coupler 154, the housing 122 will translate from right to left, as viewed in FIG. 2, in response to the coupling shock forces imposed through the mechanical cushioning unit. Buff movement of the housing 122 is, to some extent, countered by the compression springs 152, but primarily is resisted through the provision of the hydraulic cushion unit 130. In this connection, the disabling means 350 of the valves 300 maintain the ports 250260 in an open condition. This will result in the entire series of exponentially spaced ports being open. The open ports will yield a substantially linear dissipation of impact energy with a relatively low impedance level presented to movement of the high pressure cylinder 200 with respect to the piston head 210.

The housing 122 will go solid against the buff backstop ll14 through the high pressure cylinder 200 before the piston head 210 reaches the transverse barrier wall 160. Therefore the hydraulic unit is protected against overtravel.

The mechanical cushioning unit 128 as precompressed by transversely extending bars 181 may provide further axial cushioning for forces above 50,000 lbs. until the spacer arms go solid against the draft side of the barrier wall 160. At this point further axial movement of the mechanical unit is prevented and thus, like the hydraulic unit, the mechanical unit is protected against overtravel in buff.

In the event run-in train action forces are encountered, the coupler bar 154 will again impart right to left buff motion on the housing 122. The valves 300 are automatically closed, note FIG. 11, and thus a high level impedance to fluid flow from the interior of the high pressure cylinder 200 is provided in each of the ports 250 260. This high sustained impedance serves to effectively resist run-in train action.

in the event run-in is encountered over a sustained period of time, the high pressure cylinder 200 will move to a complete buff position with respect to the piston 210, note FIGS. 2 and 4, wherein the housing 122 will go solid with the buff backstop 114, as previously mentioned, to protect the hydraulic unit against overtravel. Notwithstanding this solid posture of the housing 122, further high capacity, i.e. in excess of 50,000 lbs., axial buff cushioning is provided by the precompressed mechanical cushioning member until the follower plate 158 goes solid with the barrier wall 160 through the spacer arms 176 and 178.

If run-out train action forces are occasioned on the coupler unit the housing 122 will be pulled from left to right by the coupler arm 1S4. Movement of the housing will be hydraulically impeded by closing the draft valve 402.

The housing 122 will extend, under sustained draft forces, until the follower plate 158 engages draft stops 116 and 118. Once the housing 122, however, has operatively gone solid with the draft abutment stops 116 and 118, further movement of the hydraulic unit is prevented and thus the hydraulic cylinder is prevented from overtravel in the draft direction. At this point in time there still will remain, however, high capacity draft cushioning provided by the precompressed me-' chanical draft gear 128. Once, however the transverse wall 160 goes solid with the follower plate 158, further axial draft motion is eliminated and the mechanical unit is protected in draft from overtravel.

When train action forces are relieved from the system, the draft valve 402 is biased into an open posture, note FIG. 16, and the restoring springs 148 are free to restore the housing 122 to the nonnal position at the draft or outward end of the car sill 100.

In the event of a sustained run-in locomotive braking, or pusher service, adjacent railway units may assume a misaligned posture. This misalignment may be automatically self-corrected with the subject coupling assembly by the provision of the laterally projecting abutments 182 and 184 on the coupler arm 154 which serve to transfer the line of force between adjacent units to one side of the pivot points of adjacent trucks of the units and thus create a righting couple to realign the railway vehicles with the centerline of the track.

The foregoing noted realignment is facilitated by the unique capability of the subject mechanical and hydraulic cushioning apparatus to permit longitudinal travel of the coupler bar even under sustained train action conditions and high force levels.

SUMMARY OF MAJOR ADVANTAGES In describing a preferred embodiment of the invention in conjunction with the attached drawings several advantages of the invention have been delineated.

In sum, however, a significant advantage of the invention resides in the provision of a novel cushioning apparatus having series combined mechanical and hydraulic cushioning units which are operable to cushion high capacity coupling forces and train action run-in and run-out forces while facilitating draft movement of the cushioning apparatus in response to restoring forces. I

A further significant advantage of the invention entails the provision of cushioning buff and draft forces even under sustained loading conditions where the hydraulic cushioning unit may be expended. Such cushioning is provided by the elastomeric unit which is preferably precompressed to at least 50,000 lbs. High precompression insures cushioning capacity even under high load conditions and synergistically minimizes wear of the elastomeric unit which may be occasioned by excessive low force level stroking.

The foregoing noted high level precompression is advantageously provided by compression spacer bars in combination with a retaining structure mounted within the hydraulic and mechanical cushioning housing. Such spacer bars are mounted within the housing in a posture remote from the elastomeric pad per so and enables a high degree of compression to be imparted to the pad without interfering with the operation thereof.

Another significant advantage of the invention comprises a series mounted hydraulic and mechanical cushioning unit in further series with a railway unit alignment assembly. Such series mounted structure facilitates alignment control by insuring coupler movement capacity even during train action run-in events. This capacity is even provided during sustained run-in or locomotive braking operations by the provision of the high level precompressed elastomeric cushioning pad.

Yet another significant advantage of the invention resides in the provision of a novel cushioning assembly that combines in series hydraulic and mechanical cushioning units for action in both the buff and draft directions wherein the possibility of overtravel of either the hydraulic unit or the mechanical unit is eliminated.

More specifically overtravel prevention, even for extremely high capacity loads, is internally insured, without relying upon a coupler pin or key to limit travel, by transmitting loads through the relatively thich high compression cylinder wall into sill mounted buff and draft stop members.

While the invention has been described with reference to preferred embodiments it will be appreciated by those skilled in the art that additions, deletions, modifications and substitutions, or other changes not specifically described may be made which will fall within the purview of the appended claims.

What is claimed is:

1. A railway unit cushioning apparatus comprising:

sill means directly connectable to and generally longitudinally alignable with a railway unit underframe and including,

a first side wall operable for normally projecting downwardly from the railway unit underframe,

a second side wall operable for normally projecting downwardly from the railway unit underframe and extending in a spaced parallel posture coextensively with said first side wall wherein the improvement comprises:

buff backstop means operable for normally projecting downwardly from the railway unit underframe and extending between said first and second side walls at the buff end thereof;

draft stop means connected within said sill means to the draft end of said first and second side walls of said sill means;

cushioning housing means positioned within said sill means for operative translation between said buff backstop and said draft stop means, said cushioning housing having a barrier transversely extending intermediate the ends thereof,

said transverse barrier, in combination with said and with a second impedance greater than said cushioning housing means, defining one one side first impedance in response to run-in train action a mechanical cushioning cavity at the draft end force induced relative movement of said piston of said housing, within said cylinder means, and said transverse barrier, in combination with said coupler bar means connected to the draft end of said cushioning housing means, defining on the other hi i h i a side thereof an hydraulic CUShlOIIlHg cavity at the Said oupler bar means being operable in response buff end of Said housing, wherein Said hydraulic to buff forces to transmit said buff forces through cuslllonlng cavity ls longitudinally aligned with said mechanical cushioning means and into said respect to Salcl mechanlcal Cushioning cavity, l0 cushioning housing means and effect actuation of Sald mechanlcal Cuslllonlng caVlly being further said hydraulic cushioning means until said cushfined by inwardly extending retainer means at the ioning housing goes solid with said buff backstop draft end of said cushioning housing means, and means and into Said mechanical Cushioning means to effect compression of said elastomeric cushioning means until said spacer means goes solid with said transverse barrier of said cushioning housing means; and said coupler bar means being further operable in response to draft forces to transmit draft forces into said cushioning housing means and effect actuation of said hydraulic cushioning means until said follower plate of said mechanical cushioning means goes solid with said draft stop means and into said mechanical cushioning means to effect actuation of said elastomeric cushioning means until said spacer means goes solid with said transverse barrier of said cushioning housing means, and means connected to said cushioning housing means for biasing said cushioning housing means toward the draft end of said sill means. 2. A railway unit cushioning apparatus as defined in claim 1 and further comprising:

means for mounting said elastomeric cushioning means of said mechanical cushioning means in presaid hydraulic cushioning cavity being further defined by wall means transversely extending across the buff end of said cushioning housing means;

mechanical cushioning means extending within said mechanical cushioning cavity between said transverse barrier and said inwardly projecting retainer means for cushioning both buff and draft forces,

and including follower means positioned within said mechanical cushioning cavity adjacent said retainer means,

elastomeric cushioning means extending between said transverse barrier and said follower means, and

spacer means at least partially coaxially surrounding said cushioning means and having an axial dimension less than the axial dimension of said cushioning means such that said cushioning means may be compressed until said follower means goes solid with said transverse barrier through said spacer means;

hydraulic cushioning means extending within said hydraulic cushioning cavity for cushioning both buff and draft forces and including, cylinder means coaxially extending within said hycompression within said mechanical cushioning cavity of said cushioning housing means independent of any compressive forces input to said mechanical cushioning means by said coupler bar means.

3. A railway unit cushioning apparatus as defined in said cylinder means and a relatively lower pres claim 2 wherein said means for precompression comsure fluid cavity formed within said hydraulic Fuse? cushioning cavity coaxially surrounding said cylbar mean mounted F f Sald mechalllcal inder means, cushioning cavity between said nwardly extending piston means received for translation within said retalnef means of 531d cuslllonlng housing mealls cylinder means between said transverse barrier and Sald f means for Precompressmg Sald and Said n means, elastomeric cushioning means to a magnitude of at a piston rod connected at one end to said piston least 59,000 PQ means within said cylinder means and translat- A y l Cuslllonlng means as defined in bl extending through i ll means, claim 1 wherein said means for permitting the flow of anchoring means positioned within said buff backfluid from Sald hlgll Pressure fluld y to said low stop means for anchoring the other end of said W fluid Cavity Prises: piston rod in a fixed longitudinal posture with rea plurality of P means intersecting a cylllldrlcal draulic cushioning cavity between said transverse 4O barrier and said wall means whereby a high pressure fluid cavity is formed within the interior of spect to said sill means,

means for permitting the passage of fluid from said low pressure fluid cavity to said high pressure fluid cavity at either end of said cylinder means while simultaneously preventing the flow of fluid from said high pressure fluid cavity to said low pressure fluid cavity,

means for permitting the flow of fluid from said high pressure fluid cavity to said low pressure fluid cavity, with a first impedance in response to coupling force induced relative movement of said piston means within said' cylinder means,

wall of said cylinder means and operable to impede an outward flow of fluid from the interior of said cylinder means in response to relative movement between the cylinder means and piston means; and

at least one valve mechanism carried by said cylindrical wall and operable to impede a flow of fluid moving out of the interior of said cylinder means through at least one of said port means and into said low pressure cavity in response to buff force induced, relative movement between said piston means and cylinder means,

said valve mechanism including valve closing means operable in response to fluid flow through said port means caused by run-in train action to restrict flow through at least a portion of said port means in response to run-in train action events, said valve mechanism additionally including disabling means operable, in response to flow through said port means caused by buff coupling forces, to substantially isolate said valve closing means from fluid flow through said port means and maintain at least said portion of said port means-open, and yielding biasing means operable to maintain at least said portion of said port means continuously open in the absence of forces acting on said coupling member and during operation of said disabling means in order to provide a relatively low impedance to flow through said port means. 5. A railway unit cushioning means as defined in claim 4 wherein:

said plurality of port means intersecting the cylindrical wall of said cylinder means are spaced in exponential pattern extending generally longitudinally of said cylinder means; and a plurality of ports are each provided with one of said valve mechanisms. 6. A railway unit cushioning means as defined in claim 4 and further comprising:

port means formed through said cylinder means at the draft end of said cylinder means for permitting fluid to flow from said high pressure cavity. to said low pressure cavity in response to draft force induced relative movement of said piston within said cylinder means. 7. A railway unit cushioning means as defined in claim 6 and further comprising:

, control valve means operable to control flow through said port means; said control valve means being operable, in response to run-out train action event forces acting on said coupler bar to substantially restrict fluid flow through said port means, and said control valve means being operable to maintain said port means substantially open in response to force imposed on said coupler bar by said means for biasing said cushioning housing means toward the draft end of said sill means. 8. A railway unit cushioning apparatus as defined in claim 1 wherein:

said cylinder means coaxially extending within said hydraulic cushioning cavity is fashioned with a wall thickness relatively greater than the wall thickness of the surrounding cushioning housing means, and

said buff backstop means extending inwardly within said first and second sill side walls to a posture at least partially in longitudinally blocking alignment with respect to said cylinder means wherein buff forces imparted to said cushioning housing means, at the end of the buff hydraulic cushioning stroke, will be carried at least in part through said relatively thick walled cylinder means to said buff backstop means.

9. A railway unit cushioning apparatus as defined in claim 1 and further comprising:

alignment shoulders outwardly projecting upon opposite lateral sides of said coupler bar means at the butt end thereof; bearing plate means mounted upon the draft face of said follower means, said bearing plate means including, a primary concave surface for abuttingly receiving a compatibly contoured convex surface at the butt end of said coupler bar, and a secondary convex surface fashioned within said bearing plate means on each lateral-side of said primary concave surface for abuttingly receiving a compatibly contoured convex surface of said alignment shoulders; said alignment shoulders of said coupler bar means being operable to engage said secondary convex surfaces upon swinging movement of said coupler bar means for providing longitudinal alignment control of said coupler bar means with respect to a longitudinal axis of said sill means. 10. A railway unit cushioning apparatus comprising:

sill means directly connectable to and generally longitudinally alignable with a railway unit underframe and including, a first side wall operable for normally projecting downwardly from the railway unit underframe, a second side wall operable for normally projecting downwardly from the railway unit underframe and extending in a spaced parallel posture coextensively with said first side wall wherein the improvement comprises:

buff backstop means operable for normally projecting downwardly from the railway unit underframe and extending between said first and second side walls at the buff end thereof; draft stop means connected within said sill means to the draft end of said first and second side walls of said sill means; cushioning housing means positioned within said sill means for operative translation between said buff backstop and said draft stop means, said cushioning housing having g a mechanical cushioning cavity, and a hydraulic cushioning cavity longitudinally aligned with respect to said mechanical cushioning cavmechanicalcushioning means extending within said mechanical cushioning cavity for cushioning both buff and draft forces, hydraulic cushioning means extending within said hydraulic cushioning cavity for cushioning both buff and draft forces and including, cylinder means coaxially extending within said hydraulic cushioning cavity, whereby a high pressure fluid cavity is formed within the interior of said cylinder means and a relatively lower pressure fluid cavity formed within said hydraulic cushioning cavity coaxially surrounding said cylinder means,

first cylinder head means connected to the draft end of said cylinder means;

second cylinder head means connected to the buff end of said cylinder means whereby a high pressure fluid cavity is formed within the interior of said cylinder means and a relatively lower pressure fluid cavity is formed within said hydraulic cushioning cavity coaxially surrounding said cylinder means;

piston means received for translation within said cylinder means between said first and second cylinder head means;

a piston rod connected at one end to said piston means within said cylinder means and translatably extending through said first cylinder head means;

anchoring means positioned within said buff backstop means for anchoring the other end of said piston rod in a fixed longitudinal posture with respect to said sill means;

means for permitting the passage of fluid from said low pressure fluid cavity to said high pressure fluid cavity at either end of said cylinder means while simultaneously preventing the flow of fluid from said high pressure fluid cavity to said low pressure fluid cavity;

means for permitting the flow of fluid from said high pressure fluid cavity to said low pressure fluid cavity with a first impedance in response to coupling force induced relative movement of said piston means within said cylinder means, and with a second impedance greater than said first impedance in response to run-in train action force induced relative movement of said piston within said cylinder means; and

means connected to said cushioning housing means for biasing said cushioning housing means toward the draft end of said sill means.

11. A railway unit cushioning apparatus as defined in claim 10 wherein said means for permitting the flow of fluid from said high pressure fluid cavity to said low pressure fluid cavity comprises:

a plurality of port means intersecting a cylindrical wall of said cylinder means and operable to impede an outward flow of fluid from the interior of said cylinder means in response to relative movement between said cylinder means and piston means; and

at least one valve mechanism carried by said cylindrical wall and operable to impede a flow of fluid moving out of the interior of said cylinder means through at least one of said port means and into said low pressure cavity in response to buff force induced, relative movement between said piston means and cylinder means,

said valve mechanism including valve closing means operable in response to fluid flow through said port means caused by run-in train action to restrict flow through at least a portion of said port means in response to run-in train action events,

said valve mechanism additionally including disabling means operable, in response to flow through said port means caused by buff coupling forces, to substantially isolate said valve closing means from fluid flow through said port means and maintain at least said portion of said port means open, and

yieldable biasing means operable to maintain at least said portion of said port means continuously open in the absence of forces acting on said coupling member and during operation of said disabling means in order to provide a relatively low impedance to flow through said port means.

12. A railway unit cushioning means as defined in claim 11 wherein:

said plurality of port means intersecting the cylindrical wall of said cylinder means are spaced in exponential pattern extending generally longitudinally of said cylinder means; and at least a plurality of ports each provided with one of said valve mechanisms. 13. A railway unit cushioning means as defined in claim 10 and further comprising:

port means formed through said cylinder means at the draft end of said cylinder means for permitting fluid to flow from said high pressure cavity to said low pressure cavity in response to draft force induced relative movement of said piston within said cylinder means. 14. A railway unit cushioning means as defined in claim 13 and further comprising:

control valve means operable to control flow through said port means, said control valve means being operable, in response to rin-out train action event forces to substantially restrict fluid flow through said port means, and said control valve means being operable to maintain said port means substantially open in response to force for biasing said cushioning housing means toward said draft stop means. 15. A railway unit cushioning apparatus comprising:

sill means directly connectable to and generally longitudinally alignable with a railway unit underframe and including, a first side wall operable for normally projecting downwardly from the railway unit underframe, a second side wall operable for normally projecting downwardly from the railway unit underframe and extending in a spaced parallel posture coextensively with said first side wall wherein the improvement comprises:

buff backstop means operable for normally projecting downwardly from the railway unit underframe and extending between said first and second side walls at the buff end thereof; draft stop means connected within said sill means to the draft end of said first and second side walls of said sill means; cushioning housing means positioned within said sill means for operative translation between said buff backstop and said draft stop means, said cushioning housing having a barrier transversely extending intermediate the ends thereof, said transverse barrier, in combination with said cushioning housing means, defining on one side a mechanical cushioning cavity at the draft end of said housing, said transverse barrier, in combination with said cushioning housing means, defining on the other side thereof an hydraulic cushioning cavity at the buff end of said housing, wherein said hydraulic cushioning cavity is longitudinally aligned with respect to said mechanical cushioning cavity, said mechanical cushioning cavity being further defined by inwardly extending retainer means at the draft end of said cushioning housing means, and

said hydraulic cushioning cavity being further defined by wall means transversely extending across the buff end of said cushioning housing means;

mechanical cushioning means extending within said hydraulic cushioning means extending within said hydraulic cushioning cavity for cushioning both buff and draft forces in series with said mechanical cushioning means;

couplar bar means connected to the draft end of said cushioning housing means,

said coupler bar means being operable in response to buff forces to transmit said buff forces through said mechanical cushioning means and into said cushioning housing means and effect actuation of said hydraulic cushioning means until said cushioning housing goes solid with said buff backstop means and into said mechanical cushioning means to effect compression of said elastomeric cushioning means until said spacer means foes solid with said transverse barrier of said cushioning housing means; and said coupler bar means being further operable in response to draft forces to transmit draft forces into said cushioning housing means and effect actuation of said hydraulic cushioning means until said follower plate of said mechanical cushioning means goes solid with said draft stop means and into said mechanical cushioning means to effect actuation of said elastomeric cushioning means until said spacer means goes solid with said transverse barrier of said cushioning housing means, and means connected to said cushioning housing means for biasing said cushioning housing means toward the draft end of said sill means. 16. A railway unit cushioning apparatus as defined in claim 15 and further comprising:

means for mounting said elastomeric cushioning means of said mechanical cushioning means in precompression within said mechanical cushioning cavity of said cushioning housing means independent of any compressive forces input to said mechanical cushioning menas by said coupler bar means.

17. A railway unit cushioning apparatus as defined in claim 16 wherein said means for precompression comprises:

bar insert means mounted within said mechanical cushioning cavity between said inwardly extending retainer means of said cushioning housing means and said follower means for precompressing said elastomeric cushioning means to a magnitude of at least 50,000 pounds. 

1. A railway unit cushioning apparatus comprising: sill means directly connectable to and generally longitudinally alignable with a railway unit underframe and including, a first side wall operable for normally projecting downwardly from the railway unit underframe, a second side wall operable for normally projecting downwardly from the railway unit underframe and extending in a spaced parallel posture coextensively with said first side wall wherein the improvement comprises: buff backstop means operable for normally projecting downwardly from the railway unit underframe and extending between said first and second side walls at the buff end thereof; draft stop means connected within said sill means to the draft end of said first and second side walls of said sill means; cushioning housing means positioned within said sill means for operative translation between said buff backstop and said draft stop means, said cushioning housing having a barrier transversely extending intermediate the ends thereof, said transverse barrier, in combination with said cushioning housing means, defining one one side a mechanical cushioning cavity at the draft end of said housing, said transverse barrier, in combination with said cushioning housing means, defining on the other side thereof an hydraulic cushioning cavity at the buff end of said housing, wherein said hydraulic cushioning cavity is longitudinally aligned with respect to said mechanical cushioning cavity, said mechanical cushioning cavity being further defined by inwardly extending retainer means at the draft end of said cushioning housing means, and said hydraulic cushioning cavity being further defined by wall means transversely extending across the buff end of said cushioning housing means; mechanical cushioning means extending within said mechanical cushioning cavity between said transverse barrier and said inwardly projecting retainer means for cushioning both buff and draft forces, and including follower means positioned within said mechanical cushioning cavity adjacent said retainer means, elastomeric cushioning means extending between said transverse barrier and said follower means, and spacer means at least partially coaxially surrounding said cushioning means and having an axial dimension less than the axial dimension of said cushioning means such that said cushioning means may be compressed until said follower means goes solid with said transverse barrier through said spacer means; hydraulic cushioning means extending within said hydraulic cushioning cavity for cushioning both buff and draft forces and including, cylinder means coaxially extending within said hydraulic cushioning cavity between said transverse barrier and said wall means whereby a high pressure fluid cavity is formed within the interior of said cylinder means and a relatively lower pressure fluid cavity formed within said hydraulic cushioning cavity coaxially surrounding said cylinder means, piston means received for translation within said cylinder means between said transverse barrier and said wall means, a piston rod connected at one end to said piston means within said cylinder means and translatably extending through said wall means, anchoring means positioned within said buff backstop means for anchoring the other end of said piston rod in a fixed longitudinal posture with respect to said sill means, means for permitting the passage of fluid from said low pressure fluid cavity to said high pressure fluid cavity at either end of said cylinder means while simultaneously preventing the flow of fluid from said high pressure fluid cavity to said low pressure fluid cavity, means for permitting the flow of fluid from said high pressure fluid cavity to said low pressure fluid cavity, with a first impedance in response to coupling force induced relative movement of said piston means within said cylinder means, and with a second impedance greater than said first impedance in response to run-in train action force induced relative movement of said piston within said cylinder means, and coupler bar means connected to the draft end of said cushioning housing means, said coupler bar means being operable in response to buff forces to transmit said buff forces through said mechanical cushioning means and into said cushioning housing means and effect actUation of said hydraulic cushioning means until said cushioning housing goes solid with said buff backstop means and into said mechanical cushioning means to effect compression of said elastomeric cushioning means until said spacer means goes solid with said transverse barrier of said cushioning housing means; and said coupler bar means being further operable in response to draft forces to transmit draft forces into said cushioning housing means and effect actuation of said hydraulic cushioning means until said follower plate of said mechanical cushioning means goes solid with said draft stop means and into said mechanical cushioning means to effect actuation of said elastomeric cushioning means until said spacer means goes solid with said transverse barrier of said cushioning housing means, and means connected to said cushioning housing means for biasing said cushioning housing means toward the draft end of said sill means.
 2. A railway unit cushioning apparatus as defined in claim 1 and further comprising: means for mounting said elastomeric cushioning means of said mechanical cushioning means in precompression within said mechanical cushioning cavity of said cushioning housing means independent of any compressive forces input to said mechanical cushioning means by said coupler bar means.
 3. A railway unit cushioning apparatus as defined in claim 2 wherein said means for precompression comprises: bar insert means mounted within said mechanical cushioning cavity between said inwardly extending retainer means of said cushioning housing means and said follower means for precompressing said elastomeric cushioning means to a magnitude of at least 50,000 pounds.
 4. A railway unit cushioning means as defined in claim 1 wherein said means for permitting the flow of fluid from said high pressure fluid cavity to said low pressure fluid cavity comprises: a plurality of port means intersecting a cylindrical wall of said cylinder means and operable to impede an outward flow of fluid from the interior of said cylinder means in response to relative movement between the cylinder means and piston means; and at least one valve mechanism carried by said cylindrical wall and operable to impede a flow of fluid moving out of the interior of said cylinder means through at least one of said port means and into said low pressure cavity in response to buff force induced, relative movement between said piston means and cylinder means, said valve mechanism including valve closing means operable in response to fluid flow through said port means caused by run-in train action to restrict flow through at least a portion of said port means in response to run-in train action events, said valve mechanism additionally including disabling means operable, in response to flow through said port means caused by buff coupling forces, to substantially isolate said valve closing means from fluid flow through said port means and maintain at least said portion of said port means open, and yielding biasing means operable to maintain at least said portion of said port means continuously open in the absence of forces acting on said coupling member and during operation of said disabling means in order to provide a relatively low impedance to flow through said port means.
 5. A railway unit cushioning means as defined in claim 4 wherein: said plurality of port means intersecting the cylindrical wall of said cylinder means are spaced in exponential pattern extending generally longitudinally of said cylinder means; and a plurality of ports are each provided with one of said valve mechanisms.
 6. A railway unit cushioning means as defined in claim 4 and further comprising: port means formed through said cylinder means at the draft end of said cylinder means for permitting fluid to flow from said high pressure cavity to said low pressure cavity in response to draft force induced relative movement of said piston within said cylinder means.
 7. A railway unit cushioning means as defined in claim 6 and further comprising: control valve means operable to control flow through said port means; said control valve means being operable, in response to run-out train action event forces acting on said coupler bar to substantially restrict fluid flow through said port means, and said control valve means being operable to maintain said port means substantially open in response to force imposed on said coupler bar by said means for biasing said cushioning housing means toward the draft end of said sill means.
 8. A railway unit cushioning apparatus as defined in claim 1 wherein: said cylinder means coaxially extending within said hydraulic cushioning cavity is fashioned with a wall thickness relatively greater than the wall thickness of the surrounding cushioning housing means, and said buff backstop means extending inwardly within said first and second sill side walls to a posture at least partially in longitudinally blocking alignment with respect to said cylinder means wherein buff forces imparted to said cushioning housing means, at the end of the buff hydraulic cushioning stroke, will be carried at least in part through said relatively thick walled cylinder means to said buff backstop means.
 9. A railway unit cushioning apparatus as defined in claim 1 and further comprising: alignment shoulders outwardly projecting upon opposite lateral sides of said coupler bar means at the butt end thereof; bearing plate means mounted upon the draft face of said follower means, said bearing plate means including, a primary concave surface for abuttingly receiving a compatibly contoured convex surface at the butt end of said coupler bar, and a secondary convex surface fashioned within said bearing plate means on each lateral side of said primary concave surface for abuttingly receiving a compatibly contoured convex surface of said alignment shoulders; said alignment shoulders of said coupler bar means being operable to engage said secondary convex surfaces upon swinging movement of said coupler bar means for providing longitudinal alignment control of said coupler bar means with respect to a longitudinal axis of said sill means.
 10. A railway unit cushioning apparatus comprising: sill means directly connectable to and generally longitudinally alignable with a railway unit underframe and including, a first side wall operable for normally projecting downwardly from the railway unit underframe, a second side wall operable for normally projecting downwardly from the railway unit underframe and extending in a spaced parallel posture coextensively with said first side wall wherein the improvement comprises: buff backstop means operable for normally projecting downwardly from the railway unit underframe and extending between said first and second side walls at the buff end thereof; draft stop means connected within said sill means to the draft end of said first and second side walls of said sill means; cushioning housing means positioned within said sill means for operative translation between said buff backstop and said draft stop means, said cushioning housing having a mechanical cushioning cavity, and a hydraulic cushioning cavity longitudinally aligned with respect to said mechanical cushioning cavity; mechanical cushioning means extending within said mechanical cushioning cavity for cushioning both buff and draft forces, hydraulic cushioning means extending within said hydraulic cushioning cavity for cushioning both buff and draft forces and including, cylinder means coaxially extending within said hydraulic cushioning cavity, whereby a high pressure fluid cavity is formed within the interior of said cylinder means and a relatively lower pressure fluid cavity formed within said hydraulic cushioning cavity coaxially surrounding said cylinder means, first cylinder head means connected to the draft end of said cYlinder means; second cylinder head means connected to the buff end of said cylinder means whereby a high pressure fluid cavity is formed within the interior of said cylinder means and a relatively lower pressure fluid cavity is formed within said hydraulic cushioning cavity coaxially surrounding said cylinder means; piston means received for translation within said cylinder means between said first and second cylinder head means; a piston rod connected at one end to said piston means within said cylinder means and translatably extending through said first cylinder head means; anchoring means positioned within said buff backstop means for anchoring the other end of said piston rod in a fixed longitudinal posture with respect to said sill means; means for permitting the passage of fluid from said low pressure fluid cavity to said high pressure fluid cavity at either end of said cylinder means while simultaneously preventing the flow of fluid from said high pressure fluid cavity to said low pressure fluid cavity; means for permitting the flow of fluid from said high pressure fluid cavity to said low pressure fluid cavity with a first impedance in response to coupling force induced relative movement of said piston means within said cylinder means, and with a second impedance greater than said first impedance in response to run-in train action force induced relative movement of said piston within said cylinder means; and means connected to said cushioning housing means for biasing said cushioning housing means toward the draft end of said sill means.
 11. A railway unit cushioning apparatus as defined in claim 10 wherein said means for permitting the flow of fluid from said high pressure fluid cavity to said low pressure fluid cavity comprises: a plurality of port means intersecting a cylindrical wall of said cylinder means and operable to impede an outward flow of fluid from the interior of said cylinder means in response to relative movement between said cylinder means and piston means; and at least one valve mechanism carried by said cylindrical wall and operable to impede a flow of fluid moving out of the interior of said cylinder means through at least one of said port means and into said low pressure cavity in response to buff force induced, relative movement between said piston means and cylinder means, said valve mechanism including valve closing means operable in response to fluid flow through said port means caused by run-in train action to restrict flow through at least a portion of said port means in response to run-in train action events, said valve mechanism additionally including disabling means operable, in response to flow through said port means caused by buff coupling forces, to substantially isolate said valve closing means from fluid flow through said port means and maintain at least said portion of said port means open, and yieldable biasing means operable to maintain at least said portion of said port means continuously open in the absence of forces acting on said coupling member and during operation of said disabling means in order to provide a relatively low impedance to flow through said port means.
 12. A railway unit cushioning means as defined in claim 11 wherein: said plurality of port means intersecting the cylindrical wall of said cylinder means are spaced in exponential pattern extending generally longitudinally of said cylinder means; and at least a plurality of ports each provided with one of said valve mechanisms.
 13. A railway unit cushioning means as defined in claim 10 and further comprising: port means formed through said cylinder means at the draft end of said cylinder means for permitting fluid to flow from said high pressure cavity to said low pressure cavity in response to draft force induced relative movement of said piston within said cylinder means.
 14. A railway unit cushioning means as defined in claim 13 and further comprising: controL valve means operable to control flow through said port means, said control valve means being operable, in response to rin-out train action event forces to substantially restrict fluid flow through said port means, and said control valve means being operable to maintain said port means substantially open in response to force for biasing said cushioning housing means toward said draft stop means.
 15. A railway unit cushioning apparatus comprising: sill means directly connectable to and generally longitudinally alignable with a railway unit underframe and including, a first side wall operable for normally projecting downwardly from the railway unit underframe, a second side wall operable for normally projecting downwardly from the railway unit underframe and extending in a spaced parallel posture coextensively with said first side wall wherein the improvement comprises: buff backstop means operable for normally projecting downwardly from the railway unit underframe and extending between said first and second side walls at the buff end thereof; draft stop means connected within said sill means to the draft end of said first and second side walls of said sill means; cushioning housing means positioned within said sill means for operative translation between said buff backstop and said draft stop means, said cushioning housing having a barrier transversely extending intermediate the ends thereof, said transverse barrier, in combination with said cushioning housing means, defining on one side a mechanical cushioning cavity at the draft end of said housing, said transverse barrier, in combination with said cushioning housing means, defining on the other side thereof an hydraulic cushioning cavity at the buff end of said housing, wherein said hydraulic cushioning cavity is longitudinally aligned with respect to said mechanical cushioning cavity, said mechanical cushioning cavity being further defined by inwardly extending retainer means at the draft end of said cushioning housing means, and said hydraulic cushioning cavity being further defined by wall means transversely extending across the buff end of said cushioning housing means; mechanical cushioning means extending within said mechanical cushioning cavity between said transverse barrier and said inwardly projecting retainer means for cushioning both buff and draft forces, and including follower means positioned within said mechanical cushioning cavity adjacent said retainer means, elastomeric cushioning means extending between said transverse barrier and said follower means, and spacer means at least partially coaxially surrounding said cushioning means and having an axial dimension less than the axial dimension of said cushioning means such that said cushioning means may be compressed until said follower means goes solid with said transverse barrier through said spacer means; hydraulic cushioning means extending within said hydraulic cushioning cavity for cushioning both buff and draft forces in series with said mechanical cushioning means; couplar bar means connected to the draft end of said cushioning housing means, said coupler bar means being operable in response to buff forces to transmit said buff forces through said mechanical cushioning means and into said cushioning housing means and effect actuation of said hydraulic cushioning means until said cushioning housing goes solid with said buff backstop means and into said mechanical cushioning means to effect compression of said elastomeric cushioning means until said spacer means foes solid with said transverse barrier of said cushioning housing means; and said coupler bar means being further operable in response to draft forces to transmit draft forces into said cushioning housing means and effect actuation of said hydraulic cushioning means until said follower plate of said mechanical cushioning means goes solid with said draft stop means and into said mechanicAl cushioning means to effect actuation of said elastomeric cushioning means until said spacer means goes solid with said transverse barrier of said cushioning housing means, and means connected to said cushioning housing means for biasing said cushioning housing means toward the draft end of said sill means.
 16. A railway unit cushioning apparatus as defined in claim 15 and further comprising: means for mounting said elastomeric cushioning means of said mechanical cushioning means in precompression within said mechanical cushioning cavity of said cushioning housing means independent of any compressive forces input to said mechanical cushioning menas by said coupler bar means.
 17. A railway unit cushioning apparatus as defined in claim 16 wherein said means for precompression comprises: bar insert means mounted within said mechanical cushioning cavity between said inwardly extending retainer means of said cushioning housing means and said follower means for precompressing said elastomeric cushioning means to a magnitude of at least 50,000 pounds. 